Re: [PATCH v6 5/6] arm64: add SIGSYS siginfo for compat task

AKASHI Takahiro
2014-08-22T00:44:33Z

On 08/22/2014 02:54 AM, Kees Cook wrote:
> On Thu, Aug 21, 2014 at 3:56 AM, AKASHI Takahiro
> <takahiro.akashi@linaro.org> wrote:
>> SIGSYS is primarily used in secure computing to notify tracer.
>> This patch allows signal handler on compat task to get correct information
>> with SA_SYSINFO specified when this signal is delivered.

typo: SA_SIGINFO

>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> I'm unable to test this myself, but if you've got the test suite
> passing in compat mode, then this patch must be correct. :)

Thanks.
Actually I found this bug when I ran your test programs, TRAP.handler, on 32bit userland.

-Takahiro AKASHI

> Reviewed-by: Kees Cook <keescook@chromium.org>
>
> -Kees
>
>> ---
>> arch/arm64/include/asm/compat.h | 7 +++++++
>> arch/arm64/kernel/signal32.c | 8 ++++++++
>> 2 files changed, 15 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
>> index 253e33b..c877915 100644
>> --- a/arch/arm64/include/asm/compat.h
>> +++ b/arch/arm64/include/asm/compat.h
>> @@ -205,6 +205,13 @@ typedef struct compat_siginfo {
>> compat_long_t _band; /* POLL_IN, POLL_OUT, POLL_MSG */
>> int _fd;
>> } _sigpoll;
>> +
>> + /* SIGSYS */
>> + struct {
>> + compat_uptr_t _call_addr; /* calling user insn */
>> + int _syscall; /* triggering system call number */
>> + unsigned int _arch; /* AUDIT_ARCH_* of syscall */
>> + } _sigsys;
>> } _sifields;
>> } compat_siginfo_t;
>>
>> diff --git a/arch/arm64/kernel/signal32.c b/arch/arm64/kernel/signal32.c
>> index 1b9ad02..aa550d6 100644
>> --- a/arch/arm64/kernel/signal32.c
>> +++ b/arch/arm64/kernel/signal32.c
>> @@ -186,6 +186,14 @@ int copy_siginfo_to_user32(compat_siginfo_t __user *to, const siginfo_t *from)
>> err |= __put_user(from->si_uid, &to->si_uid);
>> err |= __put_user((compat_uptr_t)(unsigned long)from->si_ptr, &to->si_ptr);
>> break;
>> +#ifdef __ARCH_SIGSYS
>> + case __SI_SYS:
>> + err |= __put_user((compat_uptr_t)(unsigned long)
>> + from->si_call_addr, &to->si_call_addr);
>> + err |= __put_user(from->si_syscall, &to->si_syscall);
>> + err |= __put_user(from->si_arch, &to->si_arch);
>> + break;
>> +#endif
>> default: /* this is just in case for now ... */
>> err |= __put_user(from->si_pid, &to->si_pid);
>> err |= __put_user(from->si_uid, &to->si_uid);
>> --
>> 1.7.9.5
>>
>
>
>